a)Left: minimum distance of orbits to the origin versus SALI. The horizontal, blue line shows the limit separating ordered from chaotic orbits. All the orbits between the two horizontal lines (orange and blue) are probably sticky orbits, which require more than 10⁴ time units of integration time, so as to reveal their true chaotic nature. b)Right: minimum distances of orbits to the origin versus minimum distances to the minimum of the effective potential, located at (R_g,0). Green color corresponds to regular motion, while red corresponds to chaotic.